Olivier KAMANA (DVM,MSc., PhD) Prevalence, hygienic status and exposure assessment of Salmonella spp. in milk and dairy chain in Rwanda Olivier KAMANA (DVM,MSc., PhD) Department of Food Safety and Quality Management UR Department of Food Safety and Food Quality UGent

1 2 3 Overview of the Presentation Introduction (Rwanda, Dairy chain, Salmonella) Results and Discussion on Selected Topics Conclusions, Recommendations and Future Perspectives 1 2 3 1

Rwanda Agriculture-based economy Rwanda, “the country of 1000 hills” Agriculture-based economy Agriculture sector employs 78.8 % of the active population Agriculture sector contributes 40 % to the GDP Livestock sector contributes up to 8.8% to the GDP 2

Why this study? Socio-economic importance of milk : cultural, source of income for farmers Reconstruction process : after civil war and genocide in 1994 2020 Vision : A national program to become a middle-income economy Agriculture sector transformation to be market oriented Milk production highly increasing : doubled in the last 10 years Food safety aspects to be taken into account to protect consumers: Salmonella threat 3

Salmonella Rod shaped bacteria Enterobacteriaceae family Only visible with a microscope (1-10μm) Intestinal tract of animals Mostly associated with milk, eggs and meat Zoonotic : transmitted to humans by animals via animal product Milk offers ideal conditions for growth Causes salmonellosis 4

Salmonellosis A redoubtable food-borne disease Responsible for 48.0% of all milk-borne disease in developed countries Fever Nausea and vomiting Abdominal pain Diarrhoea Death Consequence of lack of hygiene Situation critical in developing countries where basic hygienic conditions are not in place, and there is a lack of information on food-borne disease 5

Milk and dairy chain in Rwanda : Farms 6

Milk and dairy chain in Rwanda : Collection 7

Milk and dairy chain in Rwanda : Processing 8

Milk and dairy chain in Rwanda : Retail 9

Milk and dairy chain in Rwanda 10

Study area 11

Major objectives To assess microbiological quality and safety of milk and dairy products in Rwanda To gain insight in hygienic practices along the Rwandan milk and dairy chain to be able to attribute the measured microbiological quality and safety to the level of compliance with hygienic practices To identify the origin of contaminations in the identified bottlenecks To perform an exposure assessment to Salmonella in milk and cheese 12

Research framework 13

Results and discussion 1. To assess microbiological quality and safety of milk and dairy products in Rwanda & 2. To gain insight in hygienic practices along the Rwandan milk and dairy chain to be able to attribute the measured microbiological quality and safety to the level of compliance with hygienic practices 14

Microbiological quality and safety of raw milk  15

Microbiological quality and safety of pasteurized milk 16

Microbiological quality and safety of Gouda cheese 17

Microbiological quality and safety of boiled and fermented milk 18

Results and discussion 3. To identify the origin of contaminations in the identified bottlenecks : Milk shops and small cheese plants 19

Results and discussion Raw milk is of various origins : farms, mobile traders or collection centers Raw milk bought without prior testing Microbiological quality not meeting legal requirements 20

Results and discussion Boiling practices : fire wood, charcoal, electricity (rarely) Milk heated until foaming 21

Results and discussion 22

Results and discussion 23

Results and discussion Heat treatment enabled at least 6 Log reduction of Salmonella and Listeria monocytogenes Heat treatments highly effective Microbiological quality at selling decreased Contaminations from the environment and ineffective refrigeration 24

Origins of contaminations in milk shops 25

Origins of contaminations in cheese processing Microbiological quality and safety of raw milk not meeting legal requirements Heating treatments effective Study conducted after food safety interventions (2013) Overal microbiological quality and safety improvement Salmonella in environmental samples Salmonella in one small cheese plant 26

Origins of contaminations in cheese processing 27

Results and discussion 4. To perform an exposure assessment to Salmonella in milk and cheese 28

Consumer survey Study conducted in Musanze town Milk consumed directly on site in milk shops or bought for home consumption Milk is re-boiled in 66.7% of cases Daily frequence of consumption most in practice Consumers in different categories of age Cheese sold in supermarkets before and after 2012 Consumed also in households by different age categories of consumers Weekly frequence most in practice for cheese 29

Consumer survey 54 36 90 370 136 190 370 90 Milk buyers 90 Cheese buyers 54 36 90 370 136 190 370 30

Exposure assessment 31

7 244 Consumers in milk shops Exposure assessment 377 904 Inhabitants for Musanze district 102 034 Inhabitants Musanze town 250 508 Buyers in milk shops 7 244 Consumers in milk shops 7 cases Per day 680 cases Per year 32

18 264 Consumers in households 6 849 Young (37.5%) Exposure assessment 18 264 Consumers in households 6 849 Young (37.5%) 11 415 Adults (62.5%) 292 cases per day 341 cases per year 496 Cases per day 535 Cases per year 33

Exposure assessment 27 cases per year 47 cases per year 38% 30% 7 558 cheese consumers 1 716 Young (22.7%) 5 842 Adults (77.3%) BEFORE 2012 27 cases per year 47 cases per year 38% 30% AFTER 2012 29 cases per year 19 cases per year 34

Major conclusions Microbiological quality and safety of milk depends on the type of farming Milk collection centers contributed to increase milk quality and safety Increase of milk production enhanced the informal market Efforts to implement more processing facilities to be continued 35

Major conclusions Hygienic conditions in milk shops should be improved Interventions in the cheese sub-sector contributed significantly Coming interventions to take in consideration local habits Formal processing of « ikivuguto » 36

Major conclusions 37

Future perspectives Listeria monocytogenes especially in cheese processing Effectiveness on the FSMS in implementation Exposure assessment on other pathogens and food commodities 38

THANK YOU FOR YOUR ATTENTION Acknowledgements Prof. dr.ir. Mieke Uyttendaele Prof.dr.ir. Liesbeth Jacxsens Prof.dr.rer.nat. Anastase Kimonyo Belgian Development Agency THANK YOU FOR YOUR ATTENTION